U.S. Pat. No. 2,278,095 for Electrical Toothbrush Issued 3/31/42. This patent discloses a right angled brush mount on electrically driven drive shaft. Note the brush stem 20 is held by latch member 25 engaging notch 26.
U.S. Pat. No. 2,808,602 for Rotary Brush Issued 10/8/57. This patent discloses a rotary brush suitable for a toothbrush. The brush is at a right angle and the brush is held by spring 28 in groove 29.
U.S. Pat. No. 2,916,752 for Rotary Tooth Brush Issued 12/15/59. Disclosure is made in this patent of a friction fit of brush stem in drive shaft 12 and having a clutch 17 for variable speed.
U.S. Pat. No. 3,220,039 for Motor Driven Tooth Brush Issued 11/30/65. Disclosure is made in this patent of a removable head brush, and battery powered motor.
U.S. Pat. No. 3,757,419 for Portable Tooth Cleaner Issued 9/11/73. This patent discloses flexible torsion cable as a drive for rotary brush head.
U.S. Pat. No. 3,822,432 for Dental Hygiene Appliance Issued 7/9/74. Disclosure is made in this patent of a flexible drive shaft in a curved tubular extension, and driven by a battery.
U.S. Pat. No. 4,079,517 for Home Prophylasis Unit Issued 3/21/78. Disclosure is made in this patent of a water tight seal of the mechanism.
U.S. Pat. No. 4,420,851 for Mechanized Tooth Brush Having Movement In Two Planes. Issued 12/20/83. This patent discloses an electric tooth brush having rotary and longitudinal motion.
U.S. Pat. No. 4,619,009 for Tooth Cleaning Apparatus Issued 10/28/86. This patent resulted from P.C.T. (see Ex. A) application of Rosenstatter of Austria, abstract of which is attached hereto. Disclosure is made in this patent of a right angle head and brush mount and includes means to supply liquid (water) to brush head.